1. Field of the Invention
The present invention relates to an image processing device and an image processing program for determining whether to carry out color printing or monochrome printing to achieve a printing operation on a print sheet based on an original document.
2. Description of the Related Art
Conventionally, techniques for use with printing apparatuses to automatically determine whether an original document is a color document or a black and white document are known, where, if it is determined that the original document is a color document, printing is carried out with using inks of three colors of CMY, and if it is determined that the original document is a black and white document, printing is carried out with using an ink of a single color of K (black).
When a printing operation on a print sheet based on an original document is carried out, there may be cases where only a part of the original document is actually printed on the print sheet. For example, in a case where 1:1 scale printing of the original document is carried out with specifying a print sheet of a size smaller than the size of the original document, an actually printed part of the original document is a part of the original document corresponding to the size of the print sheet. Further, even in a case where printing is carried out with specifying a print sheet of the same size as the size of the original document, if a margin, where no image is to be printed, is present on the print sheet, the size of an area available for printing is smaller than the size of the original document, and therefore only a part of the original document is actually printed.
In such situations, the above-described conventional printing apparatuses, which determines whether to carry out color printing or black and white printing based on image data of the entire original document, carry out printing with using inks of three colors of CMY whenever it is determined that the entire original document is a color document even if an actually printed part of the original document does not contain a part that is recognized as a color document (color part). In this case, color inks are used to print a substantially black-and-white image (so-called composite black), resulting in waste of printing costs.
For example, Japanese Unexamined Patent Publication No. 1-103 (1991)-64268 (which will hereinafter be referred to as Patent Document 1) proposes that an area of an original document to be used for determining whether to carry out color printing or black and white printing is specified by the user, and the color/black-and-white determination is carried out with using only image data of the specified area. However, this method requires the user to directly specify an area of the original document to be used for the color/black-and-white determination every time printing is carried out, and thus forces the user to perform a troublesome operation.